1. Field of the Invention
The present invention relates to a pneumatic whistle, which can be used underwater or in an air medium, and is driven by pressure from a scuba diver's air tank.
2. Description of the Prior Art
Scuba (Self Contained Underwater Breathing Apparatus) diving has grown as a major sport and is also practiced for commercial, technical, scientific, and military purposes. The demand for safe and reliable scuba diving equipment has expanded tremendously in the past decade, leading to major advancements in the art.
A scuba diver's breathing apparatus typically incorporates a cylinder or tank of air carried on the scuba diver's back. The cylinder is usually pressurized with normal or atmospheric air in the range of 2250-3000 pounds per square inch (psi).
Attached to, and physically part of, every compressed air cylinder is a tank valve. The function of this valve is to permit air into or out of the cylinder through an on/off control knob.
Regulators are mounted by the diver to the tank valve. Most regulators have two stages. Each stage sequentially reduces the compressed air stored in the cylinder to levels sufficient for the diver to breathe.
The first stage of the regulator reduces air cylinder pressure from 2250-3000 psi to a constant intermediate pressure of 105-145 psi. Flexible rubber hoses, also called regulator hoses, convey this intermediate air to the second stage of the regulator. The second stage further reduces the intermediate air to breathable, or ambient, air pressure. The second stage is physically connected to the diver's mouthpiece through which breathable air is inhaled. Exhaled air is exhausted from the second stage directly into the water.
Intermediate air pressure ports on the first stage of the regulator may accommodate several regulator hoses. Each hose, however, has a constant intermediate pressure of 105-145 psi. In the example just described, the regulator hose was connected to the second stage, enabling the diver to breathe ambient air.
Purposes for which each regulator hose may be used are varied. Regulator hoses coming from the first stage may also be connected to the diver's buoyancy control device (BCD), which is an inflatable vest, jacket, or collar worn by the diver. Inflation of the BCD increases a diver's buoyancy and promotes ascent. Deflation of the BCD decreases buoyancy and promotes descent. Air for inflation of the BCD is supplied by the regulator hose connected to the first stage of the regulator.
Additionally, divers may use auxillary regulator hoses from intermediate pressure ports to power underwater tools--like chissels, hammers and drills.
In the past, underwater communication between scuba divers was principally limited to visual signals, such as hand signs or light signals. Unfortunately, hand signals are not clearly discernable at night, over great distances, or under low visibility water conditions. Similarly, underwater light signals are virtually undetectable during the day at any distance. Moreover, neither hand signs nor light signals are effective if the receiving diver is not directly viewing or is inattentive to the signaller. The inability to communicate clearly between scuba divers can have life threatening consequences.
The diving community desparately demands an economical, convenient, and reliable sound generator for safe and effective communication.
There exists a need for a sound generator to communicate: between submerged dive buddies or teams of divers; between scuba instructors and students; between submerged divers and divers or personnal at the surface; and between divers and other personnel at the surface. The need exists for this sound generator to have the capability of varying the frequency emitted in order to attract or repel marine life, as well as to enhance the effectiveness of communication between divers at various depths. In short, the diving community needs a variable sound generator which may be activated by air pressure of 105-145 psi typically found in regulator hoses attached to intermediate air pressure ports on the first stage of scuba diver's regulators.
Numerous acoustical energy generators have been developed for military purposes and which mount on underwater vehicles for marking purposes, decoy purposes, communication purposes, echo ranging purposes, and the like. However, such devices typically suffer shortcomings associated with high pressure devices, like hot combustion products and exhaust gases of rocket propulsion engines. Such devices are structurally complex, requiring numerous moving and complicated parts, rendering them generally expensive and unreliable for long and service free lives.